Telephoto zoom lens system

ABSTRACT

A telephoto zoom lens system comprising a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a stop fixedly arranged in respect to the third lens group, wherein the first lens group comprises a positive lens and a negative lens, the telephoto zoom lens sytem being arranged to be zoomed by moving the first lens group, the third lens group and the stop in the same direction and further arranged that the variation in the position of the entrance pupil to be caused at the time of zooming is small, it is possible to ensure satisfactory intensity of light in the marginal portion, and aberrations are corrected favorably.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a telephoto zoom lens system and, moreparticularly, to a telephoto zoom lens system which is compact in sizeand low in price and has a zoom ratio of about 3x.

(b) Description of the prior art:

A so-called afocal type zoom lens system is known as a telephoto zoomlens system, said afocal type zoom lens system comprising a first lensgroup having positive refractive power, a second lens group havingnegative refractive power, a third lens group having positive ornegative refractive power and a fourth lens group having positiverefractive power and being arranged to vary the focal length and tocompensate the image position by moving the second and third lens groupsalong the optical axis. However, said type of zoom lens system has adisadvantage that it is difficult to make the zoom ratio large becausethe first and fourth lens groups are kept fixed in respect to the imagesurface at the time of zooming. Besides, when the refractive power ofthe second lens group is made strong in case of said type of zoom lenssystem, it is possible to make the overall length of the lens systemshort. However, to correct aberrations favourably in that case, thenumber of lenses constituting the lens system should be made large. Inother words, said type of zoomlens system has a disadvantage that it isimpossible to make the lens system compact and, at the same time, tomake the price low.

As a method to make the overall length of a zoom lens system shortwithout making the refractive power of the second lens group strong, itis known to move the first lens group at the time of zooming, i.e., toarrange the lens system in such a way so that the overall length of thelens system varies at the time of zooming. When the above-mentioned typeof zoom lens system is arranged so that the overall length thereofbecomes satisfactorily short when the lens system is set to the shortestlength, it is convenient for carrying the lens system. In that case,however, the structure of the lens mount becomes complicated because thenumber of movable lens groups increases. Moreover, the number of lensesconstituting the lens system does not become so different compared withthe afocal type zoom lens systems. Therefore, the cost of production isnot low.

To solve the above-mentioned problems, a prior art device is provided byJapanese published unexamined patent applications Nos. 82432/78,117514/83, 19931/83, etc. In this case, the zoom lens system is arrangedto comprise three lens groups, i.e., a first lens group G₁, a secondlens group G₂ and a third lens group G₃, as shown in FIG. 1 and to bezoomed by moving the first lens group G₁ and the second lens group G₂.This lens system is arranged so that the number of lenses constitutingthe lens system is small, i.e., nine to eleven, and so that the lenssystem is compact in size and low in price. However, in said known zoomlens system, the stop is kept fixed in respect to the image surfacetogether with the third lens group G₃ and, therefore, the position ofthe entrance pupil varies largely at the time of zooming. As a result,variation of distortion becomes large and it is difficult to ensuresatisfactory intensity of light in the marginal portion when the lenssystem is set to the teleposition. This is because the position of theentrance pupil is decided by the distance between the stop and the firstlens group and, therefore, if the stop is kept fixed in respect to theimage surface as described above, the position of the entrance pupilvaries largely when the first lens group G₁ is moved. As a result, theheight of principal ray that passes the first lens group in the wideposition becomes largely different from said height in the telepositionand, consequently, distortion varies. Especially, pincushion distortionbecomes large in the teleposition, and it is difficult to correct it.Besides, lower rays are partially ecilipsed by some of lenses when thelens system is set to the teleposition and, therefore, it is difficultto ensure satisfactory intensity of light in the marginal portion.

Zoom lens systems disclosed by Japanese published unexamined patentapplications Nos. 30709/83, 88717/83, 80143/79 (Japanese publishedexamined patent application Nos. 11608/83), 156912/80 and 14213/81 arerespectively known as zoomlens systems that resemble the zoom lenssystem according to the present invention. However, in cases of saidknown zoom lens systems, the lens configuration is complicated.Especially, the number of lenses constituting the first lens group islarge, and this is not preferable for making the lens system compact.Moreover, in cases of said known zoom lens systems, the focal length inthe wide position is shorter than the focal length of standard lenssystems.

SUMMARY OF THE INVENTION

It is, therefore, a primary object of the present invention to provide atelephoto zoom lens system comprising three lens groups which isarranged compactly and can be made low in price and which is arranged sothat the variation in the position of the entrance pupil to be caused atthe time of zooming is small and it is possible to ensure satisfactoryintensity of light in the marginal portion and, at the same time,arranged so that aberrations are corrected favourably.

The telephoto zoom lens system according to the present inventioncomprises three lens groups, i.e., a first lens group having positiverefractive power, a second lens group having negative refractive powerand a third lens group having positive refractive power, and is arrangedso that the first lens group in which the lens diameter is especiallylarge is simplified. This is done by arranging the first lens group sothat it comprises one positive lens element and one negative lenselement and so that the variation in the position of the entrance pupilis minimized. This minimization is achieved by adopting a zooming methodin which the aperture stop is moved together with the third lens groupin the same direction as the moving direction of the first lens group atthe time of zooming from the wide position to the teleposition. Thetelephoto zoom lens system is thereby successfully arranged to attainboth compactness and correction of the variation in aberrations.

Besides, the telephoto zoom lens system according to the presentinvention includes both of such telephoto zoom lens systems arranged sothat the second lens group is kept fixed in respect to the image surfaceat the time of zooming and such telephoto zoom lens systems is arrangedso that the second lens group is moved in respect to the image surfaceat the time of zooming as described in detail in the following.

Each of FIGS. 2 and 3 shows the composition (including the movements oflens groups at the time of zooming) of the telephoto zoom lens systemaccording to the present invention. As shown in said figures, thetelephoto zoom lens system according to the present invention comprisesa first lens group G₁, a second lens group G₂, a third lens group G₃,and a stop S which is fixed to the third lens group G₃. At the time ofzooming from the wide position (W) to the teleposition (T), the stop Sis moved integrally with the third lens group G₃ in the same directionas the moving direction of the first lens group G₁. Therefore, it ispossible to make the variation in the distance between the first lensgroup G₁ and stop S small or to make said variation zero and,consequently, the variation in the position of the entrance pupilbecomes small. As a result, it is possible to correct distortion and toensure the intensity of light in the marginal portion.

Out of the telephoto zoom lens systems according to the presentinvention described so far, the zoom lens system shown in FIG. 2 isarranged to be zoomed from the wide position to the teleposition bykeeping the second lens group G₂ fixed in respect to the image surfaceand moving the first lens groups G₁ and the third lens group G₃ in thesame direction along the optical axis. At that time, the stop S movesintegrally with the third lens group G₃ as described before. Therefore,the variation in the distance between the first lens group G₁ and stop Sto be caused at the time of zooming can be made small as describedalready.

The telephoto zoom lens system shown in FIG. 3 is arranged to be zoomedfrom the wide position to the teleposition by integrally moving thefirst lens group G₁ and the third lens group G₃ toward the object sideand, at the same time, moving the second lens group G₂ as shown in FIG.3. At that time, the stop S also moves integrally with the third lensgroup G₃. Therefore, the distance between the first lens group G₁ andstop S does not vary at the time of zooming.

Besides, the first lens group G₁ has a large diameter and the cost ofsaid lens group accounts for a high percentage of the cost of the lenssystem as a whole. Therefore, in the present invention, the first lensgroup G₁ is arranged to comprise two lens elements, i.e., one positivelens element and one negative lens element, as described before so as tomake it possible to reduce the cost. Furthermore, the telephoto zoomlens system according to the present invention requires only one camgroove. Moreover, the number of lenses constituting the lens system as awhole is made small, i.e., eleven to twelve lenses as illustrated bypreferable embodiments to be described later. Thus, the presentinvention makes it possible to provide a telephoto zoom lens systemwhich is compact and low in price and, at the same time, which hasfavourable performance.

To correct aberrations more favourably, it is preferable to provide anarrangement so that the telephoto zoom lens system according to thepresent invention fulfills conditions (1) through (4) shown below:

    0.4<f.sub.1 /f.sub.T <0.8                                  (1)

    0.15<|f.sub.2 |/f.sub.T <0.25            (2)

    0.1<Δn.sub.d                                         ( 3)

    15<Δνd<30                                         (4)

where, reference symbol f_(T) represents the focal length of the lenssystem as a whole in the teleposition, reference symbols f₁ and f₂respectively represent the focal lengths of the first lens group G₁ andthe second lens group G₂, reference symbol Δnd represents the differencebetween the refractive indices of the positive lens element and thenegative lens element constituting the first lens group G₁, andreference symbol Δνd represents the difference between Abbe's numbers ofthe positive lens elment and the negative lens element constituting thefirst lens group G₁.

If the value defined by the condition (1) is made larger than the upperlimit thereof, the maximum amount of movement of the first lens group G₁at the time of zooming becomes large, and this is not desirable forminimizing the variation in the position of the entrance pupil. Besides,the advancing amount of the first lens group G₁ when focusing the lenssystem on an object at a short distance becomes large, and the filterdiameter becomes large. On the other hand, when the value defined by thecondition (1) is made smaller than the lower limit thereof, it isadvantageous for making the lens system compact. However, aberrationscaused by the first lens group G₁ comprising two lens elements cannot becorrected by the other lens groups.

If the value defined by the condition (2) is made larger than the upperlimit thereof, it is impossible to make the lens system as a wholecompact. If the value defined by the condition (2) is made smaller thanthe lower limit thereof, it becomes difficult to correct aberrationsunless the number of lenses constituting the second lens group G₂ isincreased.

The condition (3) is established in order to correct the imagecharacteristic and, especially, to correct the variation in thecurvature of field to be caused by zooming. If the condition (3) is notfulfilled, curvature of the field will be overcorrected in positionsnear the standard position.

The condition (4) is established in order to minimize chromaticaberration to be caused by the first lens group G₁. Especially, tofavourably correct lateral chromatic aberration of the lens system as awhole, chromatic aberration to be caused by the first lens group G₁should be made small. If the condition (4) is not fulfilled, chromaticaberration to be caused by the first lens group G₁ becomes large, and itis impossible to correct said chromatic aberration by the other lensgroups.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 showns the composition of a known telephoto zoom lens systemcomprising three lens groups;

FIGS. 2 and 3 respectively show the composition of the telephoto zoomlens system according to the present invention;

FIGS. 4 through 10 respectively show sectional views of Embodiments 1through 7 of the telephoto zoom lens system according to the presentinvention; and

FIGS. 11 through 17 respectively show graphs illustrating aberrationcurves of Embodiments 1 through 7 of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, preferred embodiments of the telephoto zoom lens system accordingto the present invention are shown below.

    ______________________________________                                        Embodiment 1                                                                  ______________________________________                                        f = 72.45˜193.00, F/3.5˜F/4.5                                     ______________________________________                                        r.sub.1 = 89.490                                                                         d.sub.1 = 2.30                                                                           n.sub.1 = 1.75520                                                                         ν.sub.1 = 27.51                          r.sub.2 = 44.643                                                                         d.sub.2 = 9.00                                                                           n.sub.2 = 1.62012                                                                         ν.sub.2 = 49.66                          r.sub.3 = -309.685                                                                       d.sub.3 = D.sub.1                                                  r.sub.4 = -970.005                                                                       d.sub.4 = 5.01                                                                           n.sub.3 = 1.75520                                                                         ν.sub.3 = 27.51                          r.sub.5 = -37.775                                                                        d.sub.5 = 1.50                                                                           n.sub.4 = 1.65160                                                                         ν.sub.4 = 58.52                          r.sub.6 = 51.873                                                                         d.sub.6 = 5.10                                                     r.sub.7 = -38.194                                                                        d.sub.7 = 1.30                                                                           n.sub.5 = 1.69680                                                                         ν.sub.5 = 55.52                          r.sub.8 = -206.631                                                                       d.sub.8 = D.sub.2                                                  r.sub.9 = 176.622                                                                        d.sub.9 = 7.05                                                                           n.sub.6 = 1.67003                                                                         ν.sub.6 = 47.25                          r.sub.10 = -27.963                                                                       d.sub.10 = 1.50                                                                          n.sub.7 = 1.78470                                                                         ν.sub.7 = 26.22                          r.sub.11 = -78.566                                                                       d.sub.11 = 0.65                                                    r.sub.12 = 31.596                                                                        d.sub.12 = 6.50                                                                          n.sub.8 = 1.51454                                                                         ν.sub.8 = 54.69                          r.sub.13 = -329.451                                                                      d.sub.13 = 2.01                                                    r.sub.14 = -151.835                                                                      d.sub.14 = 2.00                                                                          n.sub.9 = 1.80518                                                                         ν.sub.9 = 25.43                          r.sub.15 = 421.122                                                                       d.sub.15 = 26.41                                                   r.sub.16 = 90.256                                                                        d.sub.16 = 2.91                                                                          n.sub.10 = 1.74950                                                                        ν.sub.10 = 35.27                         r.sub.17 = -116.777                                                                      d.sub.17 = 6.78                                                    r.sub.18 = -26.214                                                                       d.sub.18 = 1.20                                                                          n.sub.11 = 1.77250                                                                        ν.sub.11  = 49.66                        r.sub.19 = -73.163                                                            ______________________________________                                        f               D.sub.1      D.sub.2                                          ______________________________________                                         72.45           1.514       26.713                                           118.18          21.057       14.167                                           193.00          37.860        1.200                                           f.sub.1 = 135.754, f.sub.2 = -38.165                                          f.sub.T = 193.00, f.sub.1 /f.sub.T = 0.70, |f.sub.2 |/f.    sub.T = 0.20                                                                  Δnd = 0.14, Δνd = 22.15                                        ______________________________________                                    

    ______________________________________                                        Embodiment 2                                                                  ______________________________________                                        f = 72.45˜193.00, F/3.5˜F/4.5                                     r.sub.1 = 96.453                                                                         d.sub.1 = 2.30                                                                           n.sub.1 = 1.80518                                                                         ν.sub.1 = 25.43                          r.sub.2 = 46.644                                                                         d.sub.2 = 10.00                                                                          n.sub.2 = 1.66892                                                                         ν.sub.2 = 44.98                          r.sub.3 = -302.593                                                                       d.sub.3 = D.sub.1                                                  r.sub.4 = -143.955                                                                       d.sub.4 = 5.01                                                                           n.sub.3 = 1.80518                                                                         ν.sub.3 = 25.43                          r.sub.5 = -35.535                                                                        d.sub.5 = 1.45                                                                           n.sub.4 = 1.65160                                                                         ν.sub.4 = 58.52                          r.sub.6 = 83.960                                                                         d.sub.6 = 5.10                                                     r.sub.7 = -45.391                                                                        d.sub.7 = 1.03                                                                           n.sub.5 = 1.69680                                                                         ν.sub.5 = 55.52                          r.sub.8 = 355.038                                                                        d.sub.8 = D.sub.2                                                  r.sub.9 =  143.478                                                                       d.sub.9 = 7.05                                                                           n.sub.6 = 1.66892                                                                         ν.sub.6 = 44.98                          r.sub.10 = -26.171                                                                       d.sub.10 = 1.01                                                                          n.sub.7 = 1.80518                                                                         ν.sub.7 = 25.43                          r.sub.11 = -81.941                                                                       d.sub.11 = 0.50                                                    r.sub.12 = 35.182                                                                        d.sub.12 = 6.22                                                                          n.sub.8 = 1.51633                                                                         ν.sub.8 = 64.15                          r.sub.13 = -1674.665                                                                     d.sub.13 = 5.04                                                    r.sub.14 = -384.037                                                                      d.sub.14 = 1.35                                                                          n.sub.9 = 1.80518                                                                         ν9 = 25.43                               r.sub.15 = 1056.083                                                                      d.sub.15 = 23.64                                                   r.sub.16 = 129.285                                                                       d.sub.16 = 3.03                                                                          n.sub.10 = 1.74950                                                                        ν.sub.10 = 35.27                         r.sub.17 = 97.985                                                                        d.sub.17 = 6.56                                                    r.sub.18 = -26.752                                                                       d.sub.18 = 1.06                                                                          n.sub.11 = 1.77250                                                                        ν.sub.11 = 49.66                         r.sub.19 = -63.835                                                            ______________________________________                                        f            D.sub.1      D.sub.2                                             ______________________________________                                         72.45        1.514       25.114                                              118.14       22.250       13.606                                              193.00       38.809        1.200                                              f.sub.1 = 132.056,                                                                         f.sub.2 = -36.326                                                f.sub.T = 193.00,                                                                          f.sub.1 /f.sub.T = 0.68,                                                                   |f.sub.2 |/f.sub.T = 0.19         Δn.sub.d = 0.14,                                                                     Δν.sub.d = 19.55                                        ______________________________________                                    

    ______________________________________                                        Embodiment 3                                                                  ______________________________________                                        f = 72.45˜193.00, F/3.5˜F/4.5                                     ______________________________________                                        r.sub.1 = 79.567                                                                         d.sub.1 = 2.30                                                                           n.sub.1 = 1.80518                                                                         ν.sub.1 = 25.43                          r.sub.2 = 44.857                                                                         d.sub.2 = 10.00                                                                          n.sub.2 = 1.58267                                                                         ν.sub.2 = 46.33                          r.sub.3 = -285.287                                                                       d.sub.3 = D.sub.1                                                  r.sub.4 = 337.164                                                                        d.sub.4 = 5.01                                                                           n.sub.3 = 1.80518                                                                         ν.sub.3 = 25.43                          r.sub.5 = -36.739                                                                        d.sub.5 = 1.45                                                                           n.sub.4 = 1.66755                                                                         ν.sub.4 = 41.93                          r.sub.6 = 48.075                                                                         d.sub.6 = 5.10                                                     r.sub.7 = -35.811                                                                        d.sub.7 = 1.03                                                                           n.sub.5 = 1.69680                                                                         ν.sub.5 = 55.52                          r.sub.8 = -414.819                                                                       d.sub.8 = D.sub.2                                                  r.sub.9  = 135.589                                                                       d.sub.9 = 7.05                                                                           n.sub.6 = 1.67003                                                                         ν.sub.6 = 47.25                          r.sub.10 = -26.431                                                                       d.sub.10 = 1.01                                                                          n.sub.7 = 1.80518                                                                         ν.sub.7 = 25.43                          r.sub.11 = -91.828                                                                       d.sub.11 = 0.28                                                    r.sub.12 = 34.838                                                                        d.sub.12 = 6.34                                                                          n.sub.8 = 1.61375                                                                         ν.sub.8 = 56.36                          r.sub.13 = 131.591                                                                       d.sub.13 = 30.37                                                   r.sub.14 = 291.464                                                                       d.sub.14 = 2.77                                                                          n.sub.9 = 1.83400                                                                         ν6.sub.9 = 37.16                         r.sub.15 = -97.825                                                                       d.sub.15 = 6.31                                                    r.sub.16 = -24.343                                                                       d.sub.16 = 1.06                                                                          n.sub.10 = 1.77250                                                                        ν.sub.10 = 49.66                         r.sub.17 = -75.409                                                                       d.sub.17 = 0.10                                                    r.sub.18 = 168.973                                                                       d.sub.18 = 3.89                                                                          n.sub.11  = 1.66755                                                                       ν.sub.11 = 41.93                         r.sub.19 = -247.956                                                           ______________________________________                                        f              D.sub.1 D.sub.2                                                ______________________________________                                        72.45          1.514   27.451                                                 118.14         20.771  14.400                                                 193.00         37.865  1.200                                                  ______________________________________                                        f.sub.1 = 139.437, f.sub.2 = -38.702                                          f.sub.T = 193.00, f.sub.1 /f.sub.T = 0.72, |F.sub.2 |/f.    sub.T l = 0.20                                                                Δn.sub.d = 0.22, Δν.sub.d = 20.9                               ______________________________________                                    

    ______________________________________                                        Embodiment 4                                                                  ______________________________________                                        f = 72.45˜193.00, F/3.5˜F/4.5                                     ______________________________________                                        r.sub.1 = 89.814                                                                         d.sub.1 = 2.30                                                                           n.sub.1 = 1.75520                                                                         ν.sub.1 = 27.51                          r.sub.2 = 44.870                                                                         d.sub.2 = 9.00                                                                           n.sub.2 = 1.62012                                                                         ν.sub.2 = 49.66                          r.sub.3 = -315.702                                                                       d.sub.3 = D.sub.1                                                  r.sub.4 = -361.172                                                                       d.sub.4 = 5.02                                                                           n.sub.3 = 1.75520                                                                         ν.sub.3 = 27.51                          r.sub.5 = -34.939                                                                        d.sub.5 = 1.50                                                                           n.sub.4 = 1.65160                                                                         ν.sub.4 = 58.52                          r.sub.6 = 57.174                                                                         d.sub.6 = 5.10                                                     r.sub.7 = -38.884                                                                        d.sub.7 = 1.30                                                                           n.sub.5 = 1.69680                                                                         ν.sub.5 = 55.52                          r.sub.8 = -367.847                                                                       d.sub.8 = D.sub.2                                                  r.sub.9 =  687.627                                                                       d.sub.9 = 7.05                                                                           n.sub.6 = 1.67003                                                                         ν.sub.6 = 47.25                          r.sub.10 = -25.677                                                                       d.sub.10 = 1.50                                                                          n.sub.7 = 1.78470                                                                         ν.sub.7 = 26.22                          r.sub.11 = -96.353                                                                       d.sub.11 = 0.68                                                    r.sub.12 = 54.591                                                                        d.sub.12 = 4.00                                                                          n.sub.8 = 1.51633                                                                         ν.sub.8 = 64.15                          r.sub.13 = 519.787                                                                       d.sub.13 = 0.39                                                    r.sub.14 = 44.054                                                                        d.sub.14 = 4.00                                                                          n.sub.9 = 1.51742                                                                         ν.sub.9 = 52.41                          r.sub.15 = 175.567                                                                       d.sub.15 = 34.17                                                   r.sub.16 = 70.338                                                                        d.sub.16 = 3.00                                                                          n.sub.10 = 1.80610                                                                        ν.sub.10 = 40.95                         r.sub.17 = -370.425                                                                      d.sub.17 = 6.67                                                    r.sub.18 = -29.087                                                                       d.sub.18 = 1.20                                                                          n.sub.11 = 1.77250                                                                        ν.sub.11 = 49.66                         r.sub.19 = -105.273                                                           ______________________________________                                        f              D.sub.1 D.sub.2                                                ______________________________________                                        72.45          1.514   24.038                                                 118.14         23.824  13.117                                                 193.00         41.312  1.200                                                  ______________________________________                                        f.sub.1 = 136.715, f.sub.2 = -36.372                                          f.sub.T = 193.00, f.sub.1 /f.sub.T = 0.71, |f.sub.2 |/f.    sub.T l = 0.19                                                                Δn.sub.d = 0.14, Δν.sub.d = 22.15                              ______________________________________                                    

    ______________________________________                                        Embodiment 5                                                                  ______________________________________                                        f = 72.45˜193.00, F/3.5˜F/4.5                                     r.sub.1 = 88.884                                                              d.sub.1 = 2.30 n.sub.1 = 1.80518                                                                           ν.sub.1 = 25.43                               r.sub.2 = 46.226                                                              d.sub.2 = 9.00 n.sub.2 = 1.62374                                                                           ν.sub.2 = 47.10                               r.sub.3 = -265.706                                                            d.sub.3 = D.sub.1                                                             r.sub.4 = 243.870                                                             d.sub.4 = 5.01 n.sub.3 = 1.75520                                                                           ν.sub.3 = 27.51                               r.sub.5 = -35.216                                                             d.sub.5 = 1.50 n.sub.4 = 1.66672                                                                           ν.sub.4 = 48.32                               r.sub.6 = 52.143                                                              d.sub.6 = 5.27                                                                r.sub.7 = -38.718                                                             d.sub.7 = 1.30 n.sub.5 = 1.77250                                                                           ν.sub.5 = 49.66                               r.sub.8 = -258.801                                                            d.sub.8 = D.sub.2                                                             r.sub.9 = 90.813                                                              d.sub.9 = 7.05 n.sub. 6 = 1.67003                                                                          ν.sub.6 = 47.25                               r.sub.10 = -27.536                                                            d.sub.10 = 1.50                                                                              n.sub.7 = 1.78470                                                                           ν.sub.7 = 26.22                               r.sub.11 = -117.766                                                           d.sub.11 = 0.10                                                               r.sub.12 = 37.888                                                             d.sub.12 = 6.52                                                                              n.sub.8 = 1.51823                                                                           ν.sub.8 = 58.96                               r.sub.13 = -124.108                                                           d.sub.13 = 1.56                                                               r.sub.14 = -150.179                                                           d.sub.14 = 1.96                                                                              n.sub.9 = 1.77250                                                                           ν.sub.9 = 49.66                               r.sub.15 = 432.630                                                            d.sub.15 = 31.67                                                              r.sub.16 = 77.454                                                             d.sub.16 = 2.85                                                                              n.sub.10 = 1.71736                                                                          ν.sub.10 = 29.51                              r.sub.17 = -330.833                                                           d.sub.17 = 6.62                                                               r.sub.18 = -26.590                                                            d.sub.18 = 1.20                                                                              n.sub.11 = 1.77250                                                                          ν.sub.11 = 49.66                              r.sub.19 = -76.930                                                            ______________________________________                                         f             D.sub.1 D.sub.2                                                ______________________________________                                         72.45          1.539  34.868                                                 118.14         16.770  19.637                                                 193.00         31.307   5.100                                                 ______________________________________                                        f.sub.1 = 134.554,                                                                          f.sub.2 = -41.115                                               f.sub.T = 193.00,                                                                           f.sub.1 /f.sub.T = 0.70, |f.sub.2 |/f.sub.                  T = 0.21                                                        Δn.sub.d = 0.18144,                                                                   Δν.sub.d = 21.67                                       ______________________________________                                    

    ______________________________________                                        Embodiment 6                                                                  ______________________________________                                        f = 72.45˜193.00, F/3.5˜F/4.5                                     r.sub.1 = 83.619                                                              d.sub.1 = 2.30 n.sub.1 = 1.80518                                                                           ν.sub.1 = 25.43                               r.sub.2 = 44.971                                                              d.sub.2 = 9.00 n.sub.2 = 1.62374                                                                           ν.sub.2 = 47.10                               r.sub.3 = -328.662                                                            d.sub.3 = D.sub.1                                                             r.sub.4 = 212.498                                                             d.sub.4 = 5.01 n.sub.3 = 1.75520                                                                           ν.sub.3 = 27.51                               r.sub.5 = -35.776                                                             d.sub.5 = 1.50 n.sub.4 = 1.66672                                                                           ν.sub.4 = 48.32                               r.sub.6 = 51.473                                                              d.sub.6 = 5.44                                                                r.sub.7 = -40.460                                                             d.sub.7 = 1.30 n.sub.5 = 1.77250                                                                           ν.sub.5 = 49.66                               r.sub.8 = -586.527                                                            d.sub.8 = D.sub.2                                                             r.sub.9 = 108.182                                                             d.sub.9 = 8.00 n.sub. 6 = 1.67003                                                                          ν.sub.6 = 47.25                               r.sub.10 = -27.480                                                            d.sub.10 = 1.50                                                                              n.sub.7 = 1.78470                                                                           ν.sub.7 = 26.22                               r.sub.11 = -94.106                                                            d.sub.11 = 0.10                                                               r.sub.12 = 33.462                                                             d.sub.12 = 6.51                                                                              n.sub.8 = 1.51633                                                                           ν.sub.8 = 64.15                               r.sub.13 = -154.544                                                           d.sub.13 = 1.44                                                               r.sub.14 = -139.853                                                           d.sub.14 = 1.96                                                                              n.sub.9 = 1.77250                                                                           ν.sub.9 = 49.66                               r.sub.15 = 477.511                                                            d.sub.15 = 31.53                                                              r.sub.16 = 242.882                                                            d.sub.16 = 2.82                                                                              n.sub.10 = 1.69895                                                                          ν.sub.10 = 30.12                              r.sub.17 = -129.338                                                           d.sub.17 = 6.27                                                               r.sub.18 = -22.322                                                            d.sub.18 = 1.20                                                                              n.sub.11 = 1.77250                                                                          ν.sub.11 = 49.66                              r.sub.19 = -88.565                                                            d.sub.19 = 0.10                                                               r.sub.20 = 104.480                                                            d.sub.20 = 4.07                                                                              n.sub.12 = 1.74950                                                                          ν.sub.12 = 35.27                              r.sub.21 = -417.921                                                           ______________________________________                                        f              D.sub.1 D.sub.2                                                ______________________________________                                         72.45          1.539  33.258                                                 118.14         16.115  18.682                                                 193.00         29.697   5.100                                                 ______________________________________                                        f.sub.1 = 134.062,                                                                          f.sub.2 = -40.200                                               f.sub.T = 193.00,                                                                           f.sub.1 /f.sub.T = 0.69, |f.sub.2 |/f.sub.                  T = 0.21                                                        Δn.sub.d = 0.18144,                                                                   Δν.sub.d = 21.67                                       ______________________________________                                    

    ______________________________________                                        Embodiment 7                                                                  ______________________________________                                        f = 72.45˜193.00, F/3.5˜F/4.5                                     ______________________________________                                        r.sub.1 = 98.030                                                              d.sub.1 = 2.30                                                                              n.sub.1 = 1.80518                                                                           ν.sub.1 = 25.43                                r.sub.2 = 49.206                                                              d.sub.2 = 9.00                                                                              n.sub.2 = 1.62374                                                                           ν.sub.2 = 47.10                                r.sub.3 = -217.810                                                            d.sub.3 = D.sub.1                                                             r.sub.4 = -785.453                                                            d.sub.4 = 5.01                                                                              n.sub.3 = 1.76180                                                                           ν.sub.3 = 27.11                                r.sub.5 = -34.617                                                             d.sub.5 = 1.50                                                                              n.sub.4 = 1.65160                                                                           ν.sub.4 = 58.52                                r.sub.6 = 63.100                                                              d.sub.6 = 5.57                                                                r.sub.7 = -37.019                                                             d.sub.7 = 1.28                                                                              n.sub.5 = 1.74400                                                                           ν.sub.5 = 44.73                                r.sub.8 = -240.280                                                            d.sub.8 = D.sub.2                                                             r.sub.9 = 211.096                                                             d.sub.9 = 7.05                                                                              n.sub.6 = 1.65844                                                                           ν.sub.6 = 50.86                                r.sub.10 = -29.039                                                            d.sub.10 = 1.50                                                                             n.sub.7 = 1.78472                                                                           ν.sub.7 = 25.71                                r.sub.11 = -70.499                                                            d.sub.11 = 0.10                                                               r.sub.12 = 35.714                                                             d.sub.12 = 6.50                                                                             n.sub.8 = 1.51741                                                                           ν.sub.8 = 52.41                                r.sub.13 = -434.751                                                           d.sub.13 = 1.20                                                               r.sub.14 = -164.868                                                           d.sub.14 = 2.00                                                                             n.sub.9 = 1.80518                                                                           ν.sub.9 = 25.43                                r.sub.15 = 901.042                                                            d.sub.15 = 30.44                                                              r.sub.16 = 80.736                                                             d.sub.16 = 2.91                                                                             n.sub.10 = 1.74950                                                                          ν.sub.10 = 35.27                               r.sub.17 = -115.426                                                           d.sub.17 = 7.40                                                               r.sub.18 = -30.425                                                            d.sub.18 = 1.18                                                                             n.sub.11 = 1.74400                                                                          ν.sub.11 = 44.73                               r.sub.19 = -135.183                                                           ______________________________________                                        f              D.sub.1 D.sub.2                                                ______________________________________                                         72.45          1.501  25.912                                                 118.14         14.969  12.445                                                 193.00         26.416   0.998                                                 ______________________________________                                        f.sub.1 = 136.499, f.sub.2 = -38.719                                          f.sub.T = 193.00, f.sub.1 /f.sub.T = 0.71, |f.sub.2 |/f.    sub.T = 0.20                                                                  Δn.sub.d = 0.18144, Δν.sub.d = 21.67                           ______________________________________                                    

In the respective embodiments shown above, reference symbols r₁, r₂,.... respectively represent radii of curvature of respective lenssurfaces, reference symbols d₁, d₂, .... respectively representthicknesses of respective lenses and airspaces between respectivelenses, reference symbols n₁, n₂, .... respectively represent refractiveindices of respective lenses, reference symbols ν₁, ν₂, ....respectively represent Abbe's numbers of respective lenses, andreference symbol f represents the focal length of the lens system as awhole.

Embodiment 1 has the lens configuration as shown in FIG. 4. That is, thefirst lens group G₁ comprises a cemented doublet consisting of anegative lens element and a positive lens element, the second lens groupG₂ comprises a cemented doublet, which consists of a positive lenselement and a negative lens element, and a negative lens component, thethird lens group G₃ comprises a cemented doublet, which consists of apositive lens element and a negative lens element, a positive lenscomponent, a negative lens component, a positive lens component and anegative lens component, and the stop S is fixed in the third lens groupG₃. Graphs of aberration curves of said Embodiment 1 are as shown inFIG. 11.

Embodiment 2 has the lens configuration as shown in FIG. 5 whichresembles the lens configuration of Embodiment 1. Graphs of aberrationcurves of said Embodiment 2 are as shown in FIG. 12.

Embodiment 3 has the lens configuration as shown in FIG. 6. That is, thethird lens group G₃ comprises a cemented doublet, which consists of apositive lens element and a negative lens element, a positive lenscomponent, a positive lens component, a negative lens component and apositive lens component. The other lens groups, i.e., the first lensgroup G₁ and the second lens group G₂, respectively have lensconfigurations which resemble those of Embodiment 1. Graphs ofaberration curves of said Embodiment 3 are as shown in FIG. 13.

Embodiment 4 has the lens configuration as shown in FIG. 7. That is, thethird lens group G₃ comprises a cemented doublet, which consists of apositive lens element and a negative lens element, a positive lenscomponent, a positive lens component, a positive lens component and anegative lens component. Graphs of aberration curves of said Embodiment4 are as shown in FIG. 14.

Embodiment 5 has the lens configuration as shown in FIG. 8 whichresembles the lens configuration of Embodiment 1. Graphs of aberrationcurves of said Embodiment 5 are as shown in FIG. 15.

Embodiment 6 has the lens configuration as shown in FIG. 9. That is, thethird lens group G₃ comprises a cemented doublet, which consists of apositive lens element and a negative lens element, a positive lenscomponent, a negative lens component, a positive lens component, anegative lens component and a positive lens component. The first lensgroup G₁ and the second lens group G₂ respectively have lensconfigurations which resemble those of Embodiment 1. Graphs ofaverration curves of said Embodiment 6 are as shown in FIG. 16.

Embodiment 7 has the lens configuration as shown in FIG. 10 whichresembles the lens configuration of Embodiment 1. Graphs of aberrationcurves of said Embodiment 7 are as shown in FIG. 17.

Out of said embodiments, Embodiments 1 through 4 are respectivelyarranged to be zoomed by moving the lens groups as shown in FIG. 2.Embodiments 5 through 7 are respectively arranged to be zoomed by movingthe lens groups as shown in FIG. 3.

As described so far, the telephoto zoom lens system according to thepresent invention is arranged to be zoomed by moving the first lensgroup and the third lens group in the same direction. Therefore, thenumber of lens group to be moved independently is small, andsubstantially only one cam groove is required for moving the lensgroups. Besides, the number of lenses constituting the lens system issmall, i.e., eleven to twelve. Thus, the present invention makes itpossible to provide a telephoto zoom lens system which is low in price.Furthermore, the variation in the position of the entrance pupil to becaused at the time of zooming is small. Therefore, the variation indistortion is small, and it is possible to ensure satisfactory intensityof light in the marginal portion when the lens system is set to theteleposition.

We claim:
 1. A telephoto zoom lens system comprising:a first lens grouparranged on the extreme object side, consisting of a positive lens and anegative lens, and having positive refractive power as a whole; a secondlens group having negative refractive power; a third lens group arrangedon the extreme image side, and including a first subgroup havingpositive refractive power and a second subgroup having negativerefractive power arranged consecutively from the object side with asubstantial airspace reserved therebetween; said first subgroupincluding a cemented doublet, said second subgroup including a negativelens, said airspace reserved between the first and second subgroupsbeing fixed, a stop being fixedly spaced a distance from any lens in thethird lens group, and the first lens group, the third lens group and thestop being moved in the same direction for varying the focal length ofthe telephoto zoom lens system.
 2. A telephoto zoom lens systemaccording to claim 1 wherein said second lens group is kept fixed inrespect to the image surface at the time of zooming.
 3. A telephoto zoomlens system according to claim 2 fulfilling the conditions (1) through(4) shown below:

    0.4<f.sub.1 /f.sub.T <0.8                                  (1)

    0.15<|f.sub.2 |/f.sub.T <0.25            (2)

    0.1<Δnd                                              (3)

    15<Δνd<30                                         (4)

where, reference symbol f_(T) represents the focal length of the lenssystem as a whole in the teleposition, reference symbols f₁ and f₂respectively represent the focal lengths of the first lens group and thesecond lens group, reference symbol Δnd represents the differencebetween the refractive indices of the positive lens and the negativelens constituting the first lens group, and reference symbol Δνdrepresents the difference between Abbe's numbers of the positive lensand the negative lens constituting the first lens group.
 4. A telephotozoom lens system according to claim 3 wherein said second lens groupcomprises a cemented doublet, which consists of a positive lens elementand a negative lens element, and a negative lens component, and saidthird lens group comprises a cemented doublet, which consists of apositive lens element and a negative lens element, a positive lenscomponent, a positive lens component, a negative lens component and apositive lens component, said telephoto zoom lens system having thefollowing numerical data:

    ______________________________________                                        f = 72.45˜193.00, F/3.5˜F/4.5                                     ______________________________________                                        r.sub.1 = 79.567                                                              d.sub.1 = 2.30                                                                              n.sub.1 = 1.80518                                                                           ν.sub.1 = 25.43                                r.sub.2 = 44.857                                                              d.sub.2 = 10.00                                                                             n.sub.2 = 1.58267                                                                           ν.sub.2 = 46.33                                r.sub.3 = -285.287                                                            d.sub.3 = D.sub.1                                                             r.sub.4 = 337.164                                                             d.sub.4 = 5.01                                                                              n.sub.3 = 1.80518                                                                           ν.sub.3 = 25.43                                r.sub.5 = -36.739                                                             d.sub.5 = 1.45                                                                              n.sub.4 = 1.66755                                                                           ν.sub.4 = 41.93                                r.sub.6 = 48.075                                                              d.sub.6 = 5.10                                                                r.sub.7 = -35.811                                                             d.sub.7 = 1.03                                                                              n.sub.5 = 1.69680                                                                           ν.sub.5 = 55.52                                r.sub.8 = -414.819                                                            d.sub.8 = D.sub.2                                                             r.sub.9 = 135.589                                                             d.sub.9 = 7.05                                                                              n.sub.6 =  1.67003                                                                          ν.sub.6 = 47.25                                r.sub.10 = -26.431                                                            d.sub.10 = 1.01                                                                             n.sub.7 = 1.80518                                                                           ν.sub.7 = 25.43                                r.sub.11 = -91.828                                                            d.sub.11 = 0.28                                                               r.sub.12 = 34.838                                                             d.sub.12 = 6.34                                                                             n.sub.8 = 1.61375                                                                           ν.sub.8 = 56.36                                r.sub.13 = 131.591                                                            d.sub.13 = 30.37                                                              r.sub.14 = 291.464                                                            d.sub.14 = 2.77                                                                             n.sub.9 = 1.83400                                                                           ν.sub.9 = 37.16                                r.sub.15 = -97.825                                                            d.sub.15 = 6.31                                                               r.sub.16 = -24.343                                                            d.sub.16 = 1.06                                                                             n.sub.10 = 1.77250                                                                          ν.sub.10 = 49.66                               r.sub.17 = -75.409                                                            d.sub.17 = 0.10                                                               r.sub.18 = 168.973                                                            d.sub.18 = 3.89                                                                             n.sub.11 = 1.66755                                                                          ν.sub.11 = 41.93                               r.sub.19 = -247.956                                                           ______________________________________                                        f              D.sub.1  D.sub.2                                               ______________________________________                                         72.45          1.514  27.451                                                 118.14         20.771  14.400                                                 193.00         37.865   1.200                                                 ______________________________________                                        f.sub.1 = 139.437, f.sub.2 = -38.702                                          f.sub.T = 193.00, f.sub.1 /f.sub.T = 0.72, |f.sub.2 |/f.    sub.T = 0.20                                                                  Δn.sub.d = 0.22, Δν.sub.d = 20.9                               ______________________________________                                    

where, reference symbols r₁ through r₁₉ respectively represent radii ofcurvautre of respective lens surfaces, reference symbols d₁ through d₁₈respectively represent thicknesses of respective lenses and airspacesbetween respective lenses, reference symbols n₁ through n₁₁ respectivelyrepresent refractive indices of respective lenses, reference symbols ν₁through ν₁₁ respectively represent Abbe's numbers of respective lenses,and reference symbol ν represents the focal lengthof the lens sysem as awhole.
 5. A telephoto zoom lens system according to claim 3 wherein saidsecond lens group comprises a cemented doublet, whick consists of apositive lens element and a negative lens element, and a negative lenscomponent, and said third lens group comprises a cemented doublet, whichconsists of a positive lens element and a negative lens element, apositive lens component, a positive lens component, said telephoto zoomlens system having the following numerical data:

    ______________________________________                                        f ==72.45˜193.00, F/3.5˜F/4.5                                     ______________________________________                                        r.sub.1 = 89.814                                                                         d.sub.1 = 2.30                                                                           n.sub.1 = 1.75520                                                                         ν.sub.1 = 27.51                          r.sub.2 = 44.870                                                                         d.sub.2 = 9.00                                                                           n.sub.2 = 1.62012                                                                         ν.sub.2 = 49.66                          r.sub.3  = -315.702                                                                      d.sub.3 = D.sub.1                                                  r.sub.4 = -361.172                                                                       d.sub.4 = 5.02                                                                           n.sub.3 = 1.75520                                                                         ν.sub.3 = 27.51                          r.sub.5 = -34.939                                                                        d.sub.5 = 1.50                                                                           n.sub.4 = 1.65160                                                                         ν.sub.4 = 58.52                          r.sub.6 = 57.174                                                                         d.sub.6 = 5.10                                                     r.sub.7 = -38.884                                                                        d.sub.7 = 1.30                                                                           n.sub.5 = 1.69680                                                                         ν.sub.5 = 55.52                          r.sub.8 = -367.947                                                                       d.sub.8 = D.sub.2                                                  r.sub.9 =  687.627                                                                       d.sub.9 = 7.05                                                                           n.sub.6 = 1.67003                                                                         ν.sub.6 = 47.25                          r.sub.10 = -25.677                                                                       d.sub.10 = 1.50                                                                          n.sub.7 = 1.78470                                                                         ν.sub.7 = 26.22                          r.sub.11 = -96.353                                                                       d.sub.11 = 0.68                                                    r.sub.12 = 54.591                                                                        d.sub.12 = 4.00                                                                          n.sub.8 = 1.51633                                                                         ν.sub.8 = 64.15                          r.sub.13 = 519.787                                                                       d.sub.13 = 0.39                                                    r.sub.14 = 44.054                                                                        d.sub.14 = 4.00                                                                          n.sub.9 = 1.51742                                                                         ν.sub.9 = 52.41                          r.sub.15 = 175.567                                                                       d.sub.15 = 34.17                                                   r.sub.16 = 70.338                                                                        d.sub.16 = 3.00                                                                          n.sub.10 = 1.80610                                                                        ν.sub.10 = 40.95                         r.sub.17 = -370.425                                                                      d.sub.17 = 6.67                                                    r.sub.18 = -29.087                                                                       d.sub.18 = 1.20                                                                          n.sub.11 = 1.77250                                                                        ν.sub.11 = 49.66                         r.sub.19 = -105.273                                                           ______________________________________                                        f              D.sub.1 D.sub.2                                                ______________________________________                                         72.45          1.514  24.038                                                 118.14         23.824  13.117                                                 193.00         41.312   1.200                                                 ______________________________________                                        f.sub.1 = 136.715, f.sub.2 = -36.372                                          f.sub.T = 193.00, f.sub.1 /f.sub.T = 0.71, |f.sub.2 |/f.    sub.T = 0.19                                                                  Δn.sub.d = 0.14, Δν.sub.d = 22.15                              ______________________________________                                    

where, reference symbols r₁ through r₁₉ respectively represent radii ofcurvature of respective lens surfaces, reference symbols d₁ through d₁₈respectively represent thicknesses of respective lenses and airspacesbetween respective lenses, reference symbols n₁ through n₁₁ respectivelyrepresent refractive indices of respective lenses, reference symbols ν₁through ν₁₁ respectively represent Abbe's numbers of respective lenses,and reference symbol f represents the focal length of the lens system asa whole.
 6. A telephoto zoom lens system according to claim 3 whereinsaid second lens group comprises a cemented doublet, which consists of apositive lens element and a negative lens element, and a negative lenscomponent, and said third lens group comprises a cemented doublet, whichconsists of a positive lens element and a negative lens element, apositive lens component, a negative lens component, a positive lenscomponent and a negative lens component, said telephoto zoom lens systemhaving the following numerical data:

    ______________________________________                                        f = 72.45˜193.00, F/3.5˜F/4.5                                     ______________________________________                                        r.sub.1 = 89.490                                                                         d.sub.1 = 2.30                                                                           n.sub.1 = 1.75520                                                                         ν.sub.1 = 27.51                          r.sub.2 = 44.643                                                                         d.sub.2 = 9.00                                                                           n.sub.2 = 1.62012                                                                         ν.sub.2 = 49.66                          r.sub.3 = -309.685                                                                       d.sub.3 = D.sub.1                                                  r.sub.4 = -970.005                                                                       d.sub.4 = 5.01                                                                           n.sub.3 = 1.75520                                                                         ν.sub.3 = 27.51                          r.sub.5 = -37.775                                                                        d.sub.5 = 1.50                                                                           n.sub.4 = 1.65160                                                                         ν.sub.4 = 58.52                          r.sub.6 = 51.873                                                                         d.sub.6 = 5.10                                                     r.sub.7 = -38.194                                                                        d.sub.7 = 1.30                                                                           n.sub.5 = 1.69680                                                                         ν.sub.5 = 55.52                          r.sub.8 = -206.631                                                                       d.sub.8 = D.sub.2                                                  r.sub.9 = 176.622                                                                        d.sub.9 = 7.05                                                                           n.sub.6 = 1.67003                                                                         ν.sub.6 = 47.25                          r.sub.10 = -27.963                                                                       d.sub.10 = 1.50                                                                          n.sub.7 = 1.78470                                                                         ν.sub.7 = 26.22                          r.sub.11 = -78.566                                                                       d.sub.11 = 0.65                                                    r.sub.12 = 31.596                                                                        d.sub.12 = 6.50                                                                          n.sub.8 = 1.51454                                                                         ν.sub.8 = 54.69                          r.sub.13 = -329.451                                                                      d.sub.13 = 2.01                                                    r.sub.14 = -151.835                                                                      d.sub.14 = 2.00                                                                          n.sub.9 = 1.80518                                                                         ν.sub.9 = 25.43                          r.sub.15 = 421.122                                                                       d.sub.15 = 26.41                                                   r.sub.16 = 90.256                                                                        d.sub.16 = 2.91                                                                          n.sub.10 = 1.74950                                                                        ν.sub.10 = 35.27                         r.sub.17 = -116.777                                                                      d.sub.17 = 6.78                                                    r.sub.18 = -26.214                                                                       d.sub.18 = n.sub.11 = 1.77250                                                                        ν.sub.11 = 49.66                         r.sub.19 = -73.163                                                            ______________________________________                                        f              D.sub.1 D.sub.2                                                ______________________________________                                         72.45          1.514  26.713                                                 118.18         21.057  14.167                                                 193.00         37.860   1.200                                                 ______________________________________                                        f.sub.1 = 135.754, f.sub.2 = -38.165                                          f.sub.T = 193.00, f.sub.1 /f.sub.T = 0.70, |f.sub.2 |/f.    sub.T = 0.20                                                                  Δn.sub.d = 0.14, Δν.sub.d = 22.15                              ______________________________________                                    

where, reference symbols r₁ through r₁₉ respectively represent radii ofcurvature of respective lens surfaces, reference symbols d₁ through d₁₈respectively represent thicknesses of respective lenses and airspacesbetween respective lenses, reference symbols n₁ through n₁₁ respectivelyrepresent refractive indices of respective lenses, reference symbols ν₁through ν₁₁ respectively represent Abbe's nubmers of respective lenses,and reference symbol f represnets the focal length of the lens system asa whole.
 7. A telephoto zoom lens system according to claim 3 whereinsaid second lens group comprises a cemented doublet, which consists of apositive lens element and a negative lens element, and a negative lenscomponent, and said third lens group comprises a cemented doublet, whichconsists of a positive lens element and a negative lens element, apositive lens component, a negative lens component, a positive lenscomponent and a negative lens component, said telephoto zoom lens systemhaving the following numerical data:

    ______________________________________                                        f = 72.45˜193.00, F/3.5˜F/4.5                                     ______________________________________                                        r.sub.1 = 96.453                                                                          d.sub.1 = 2.30                                                                          n.sub.1 = 1.80518                                                                         ν.sub.1 = 25.43                          r.sub.2 = 46.644                                                                          d.sub.2 = 10.00                                                                         n.sub.2 = 1.66892                                                                         ν.sub.2 = 44.98                          r.sub.3 = -302.593                                                                        d.sub.3 = D.sub.1                                                 r.sub.4 = -143.955                                                                        d.sub.4 = 5.01                                                                          n.sub.3 = 1.80518                                                                         ν.sub.3 = 25.43                          r.sub.5 = -35.535                                                                         d.sub.5 = 1.45                                                                          n.sub.4 = 1.65160                                                                         ν.sub.4 = 58.52                          r.sub.6 = 83.960                                                                          d.sub.6 = 5.10                                                    r.sub.7 = -45.391                                                                         d.sub.7 = 1.03                                                                          n.sub.5 = 1.69680                                                                         ν.sub.5 = 55.52                          r.sub.8 = 355.038                                                                         d.sub.8 = D.sub.2                                                 r.sub.9 = 143.478                                                                         d.sub.9 = 7.05                                                                          n.sub.6 = 1.66892                                                                         ν.sub.6 = 44.98                          r.sub.10 = -26.171                                                                        d.sub.10 = 1.01                                                                         n.sub.7 = 1.80518                                                                         ν.sub.7 = 25.43                          r.sub.11 = -81.941                                                                        d.sub.11 = 0.50                                                   r.sub.12 = 35.182                                                                         d.sub.12 = 6.22                                                                         n.sub.8 = 1.51633                                                                         ν.sub.8 = 64.15                          r.sub.13 = -1674.665                                                                      d.sub.13 = 5.04                                                   r.sub.14 = -384.037                                                                       d.sub.14 = 1.35                                                                         n.sub.9 = 1.80518                                                                         ν.sub.9 = 25.43                          r.sub.15 = 1056.083                                                                       d.sub.15 = 23.64                                                  r.sub.16 = 129.285                                                                        d.sub.16 = 3.03                                                                         n.sub.10 = 1.74950                                                                        ν.sub.10 = 35.27                         r.sub.17 = -97.985                                                                        d.sub.17 = 6.56                                                   r.sub.18 = -26.752                                                                        d.sub.18 = 1.06                                                                         n.sub.11 =  1.77250                                                                       ν.sub.11 = 49.66                         r.sub.19 = -63.835                                                            ______________________________________                                        f              D.sub.1 D.sub.2                                                ______________________________________                                         72.45          1.514  25.114                                                 118.14         22.250  13.606                                                 193.00         38,809   1.200                                                 ______________________________________                                        f.sub.1 = 132.056, f.sub.2 = -36.326                                          f.sub.T = 193.00, f.sub.1 /f.sub.T = 0.68, |f.sub.2 |/f.    sub.T = 0.19                                                                  Δn.sub.d = 0.14, Δν.sub.d = 19.55                              ______________________________________                                    

where, reference symbols r₁ through r₁₉ respectively represent radii ofcurvature of respective lens surfaces, reference symbols d₁ through d₁₈respectively represent thicknesses of respective lenses and airspacesbetween respective lenses, reference symbols n₁ through n₁₁ respectivelyrepresent refractive indices of respective lenses, reference symbols ν₁through ν₁₁ respectively represent Abbe's numbers of respective lenses,and reference symbol f represents the focal length of the lens system asa whole.
 8. A telephoto zoom lens system according to claim 1 whereinsaid first lens group and said third lens group are integrally moved atthe time of zooming.
 9. A telephoto zoom lens system according to claim8 fulfilling the conditions (1) through (4) shown below:

    0.4<f.sub.1 /f.sub.T <0.8                                  (1)

    0.15<|f.sub.2 |/f.sub.T <0.25            (2)

    0.1<Δnd                                              (3)

    15<Δνd<30                                         (4)

where, reference symbol f_(T) represents the focal length of the lenssystem as a whole in the teleposition, reference symbols f₁ and f₂respectively represent the focal lengths of the first lens group and thesecond lens group, reference sybmol Δnd represents the differencebetween the refractive indices of the positive lens and the negativelens constituting the first lens group, and reference symbol Δνdrepresents the difference between Abbe's numbers of the positive lensand the negative lens constituting the first lens group.
 10. A telephotozoom lens system according to claim 9 wherein said second lens groupcomprises a cemented doublet, which consists of a positive lens elementand a negative lens element, and a negative lens component, and saidthird lens group comprises a cemented doublet, which consists of apositive lens element and a negative lens element, a positive lenscomponent, a negative lens compoennt, a positive lens component and anegative lens component, said telephoto zoom lens system having thefollowing numerical data:

    ______________________________________                                        f = 72.45˜193.00, F/3.5˜F/4.5                                     ______________________________________                                        r.sub.1 = 88.884                                                                         d.sub.1 = 2.30                                                                          n.sub.1 = 1.80518                                                                          ν.sub.1 = 25.43                          r.sub.2 = 46.226                                                                         d.sub.2 = 9.00                                                                          n.sub.2 = 1.62374                                                                          ν.sub.2 = 47.10                          r.sub.3 = -265.706                                                                       d.sub.3 = D.sub.1                                                  r.sub.4 = 243.870                                                                        d.sub.4 = 5.01                                                                          n.sub.3 = 1.75520                                                                          ν.sub.3 = 27.51                          r.sub.5 = -35.216                                                                        d.sub.5 = 1.50                                                                          n.sub.4 = 1.66672                                                                          ν.sub.4 = 48.32                          r.sub.6 = 52.143                                                                         d.sub.6 = 5.27                                                     r.sub.7 = -38.718                                                                        d.sub.7 = 1.30                                                                          n.sub.5 = 1.77250                                                                          ν.sub.5 = 49.66                          r.sub.8 = -258.801                                                                       d.sub.8 = D.sub.2                                                  r.sub.9 = 90.813                                                                         d.sub.9 = 7.05                                                                          n.sub.6 = 1.67003                                                                          ν.sub.6 = 47.25                          r.sub.10 = -27.536                                                                       d.sub.10 = 1.50                                                                         n.sub.7 = 1.78470                                                                          ν.sub.7 = 26.22                          r.sub.11 = -117.766                                                                      d.sub.11 = 0.10                                                    r.sub.12 = 37.888                                                                        d.sub.12 = 6.52                                                                         n.sub.8 = 1.51823                                                                          ν.sub.8 = 58.96                          r.sub.13 = -124.108                                                                      d.sub.13 = 1.56                                                    r.sub.14 = -150.179                                                                      d.sub.14 = 1.96                                                                         n.sub.9 = 1.77250                                                                          ν.sub.9 = 49.66                          r.sub.15 = 432.630                                                                       d.sub.15 = 31.67                                                   r.sub.16 = 77.454                                                                        d.sub.16 = 2.85                                                                         n.sub.10 = 1.71736                                                                         ν.sub.10 = 29.51                         r.sub.17 = -330.833                                                                      d.sub.17 = 6.62                                                    r.sub.18 = -26.590                                                                       d.sub.18 = 1.20                                                                         n.sub.11 =  1.77250                                                                        ν.sub.11 = 49.66                         r.sub.19 = -76.930                                                            ______________________________________                                        f              D.sub.1 D.sub.2                                                ______________________________________                                         72.45          1.539  34.868                                                 118.14         16.770  19.637                                                 193.00         31.307   5.100                                                 ______________________________________                                        f.sub.1 = 134.554, f.sub.2 = -41.115                                          f.sub.T = 193.00, f.sub.1 /f.sub.T = 0.70 , |f.sub.2 |/f    .sub.T = 0.21                                                                 Δn.sub.d = 0.18144, Δν.sub.d = 21.67                           ______________________________________                                    

where, reference symbols r₁ through r₁₉ respectively represent radii ofcurvature of respective lens surfaces, reference symbols d₁ through d₁₈respectively represent thicknesses of respective lenses and airspacesbetween respective lenses, reference symbols n₁ through n₁₁ respectivelyrepresent refractive indices of respective lenses, reference symbols ν₁through ν₁₁ respectively represent Abbe's numbers of respective lenses,and reference symbol f represents the focal length of the lens system asa whole.
 11. A telephoto zoom lens system according to claim 9 whereinsaid second lens group comprises a cemented doublet, which consists of apositive lens element and a negative lens element, and a negative lenscomponent, and said third lens group comprises a cemented doublet, whichconsists of a positive lens element and a negative lens element, apositive lens component, a negative lens component, a positive lenscomponennt, a negative lens component and a positive lens component,said telephoto zoom lens system having the following numerical data:

    ______________________________________                                        f = 72.45˜193.00, F/3.5˜F/4.5                                     ______________________________________                                        r.sub.1 = 83.619                                                                         d.sub.1 = 2.30                                                                           n.sub.1 = 1.80518                                                                         ν.sub.1 = 25.43                          r.sub.2 = 44.971                                                                         d.sub.2 = 9.00                                                                           n.sub.2 = 1.62374                                                                         ν.sub.2 = 47.10                          r.sub.3 = -328.662                                                                       d.sub.3 = D.sub.1                                                  r.sub.4 = 212.498                                                                        d.sub.4 = 5.01                                                                           n.sub.3 = 1.75520                                                                         ν.sub.3 = 27.51                          r.sub. 5 = -35.776                                                                       d .sub.5 = 1.50                                                                          n .sub.4 = 1.66672                                                                        ν.sub.4 = 48.32                          r.sub.6 = 51.473                                                                         d.sub.6 = 5.44                                                     r.sub. 7 = -40.460                                                                       d.sub. 7 = 1.30                                                                          n.sub.5 = 1.77250                                                                         ν.sub.5 = 49.66                          r.sub.8 = -586.527                                                                       d.sub.8 = D.sub.2                                                  r.sub.9  = 108.182                                                                       d.sub.9 = 8.00                                                                           n.sub.6 = 1.67003                                                                         ν.sub.6 = 47.25                          r.sub.10 = -27.480                                                                       d.sub.10 = 1.50                                                                          n.sub.7 = 1.78470                                                                         ν.sub.7 = 26.22                          r.sub.11 = -94.106                                                                       d.sub.11 = 0.10                                                    r.sub.12 = 33.462                                                                        d.sub.12 = 6.51                                                                          n.sub. 8 = 1.51633                                                                        ν.sub.8 = 64.15                          r.sub.13 = -154.544                                                                      d.sub.13 = 1.44                                                    r.sub.14 = -139.853                                                                      d.sub.14 = 1.96                                                                          n.sub.9 = 1.77250                                                                         ν.sub.9 = 49.66                          r.sub.15 = 477.511                                                                       d.sub.15 = 31.53                                                   r.sub.16 = 242.882                                                                       d.sub.16 = 2.82                                                                          n.sub.10 = 1.69895                                                                        ν.sub.10 = 30.12                         r.sub.17 = -129.338                                                                      d.sub.17 = 6.27                                                    r.sub.18 = -22.322                                                                       d.sub.18 = 1.20                                                                          n.sub. 11 = 1.77250                                                                       ν.sub.11 = 49.66                         r.sub.19 = -88.565                                                                       d.sub.19 = 0.10                                                    r.sub.20 = 104.480                                                                       d.sub.20 = 4.07                                                                          n.sub.12 = 1.74950                                                                        ν.sub.12 = 35.27                         r.sub.21 = -417.921                                                           ______________________________________                                        f             D.sub.1      D.sub.2                                            ______________________________________                                         72.45         1.539       33.258                                             118.14        16.115       18.682                                             193.00        29.697        5.100                                             f.sub.1 = 134.062,                                                                          f.sub.2 = -40.200                                               f.sub.T = 193.00,                                                                           f.sub.1 /f.sub.T = 0.69,                                                                   |f.sub.2 |/f.sub.T = 0.21        Δn.sub.d = 0.18144,                                                                   Δν.sub.d = 21.67                                       ______________________________________                                    

where, reference symbols r₁ through r₂₁ respectively represent radii ofcurvature of respective lens surfaces, reference symbols d₁ through d₂₀respectively represent thicknesses of respective lenses and airspacesbetween respective lenses, reference symbols n₁ through n₁₂ respectivelyrepresent refractive indices of respective lenses, reference symbols ν₁through ν₁₂ respectively represent Abbe's numbers of respective lenses,and reference symbol f represents the focal length of the lens system asa whole.
 12. A telephoto zoom lens system according to claim 9 whereinsaid second lens group comprises a cemented doublet, which consists of apositive lens element and a negative lens element, and a negative lenscomponent, and said third lens group comprises a cemented doublet, whichconsists of a positive lens element and a negative lens element, apositive lens component, a negative lens component, a positive lenscomponent and a negative lens component, said telephoto zoom lens systemhaving the following numerical data:

    ______________________________________                                        f = 72.45˜193.00, F/3.5˜F/4.5                                     ______________________________________                                        r.sub.1 = 98.030                                                                         d.sub.1 = 2.30                                                                           n.sub.1 = 1.80518                                                                         ν.sub.1 = 25.43                          r.sub.2 = 49.206                                                                         d.sub.2 = 9.00                                                                           n.sub.2 = 1.62374                                                                         ν.sub.2 = 47.10                          r.sub.3 = -217.810                                                                       d.sub.3 = D.sub.1                                                  r.sub.4 = -785.453                                                                       d.sub.4 = 5.01                                                                           n.sub.3 = 1.76180                                                                         ν.sub.3 = 27.11                          r.sub.5 = -34.617                                                                        d.sub.5 = 1.50                                                                           n.sub.4 = 1.65160                                                                         ν.sub.4 = 58.52                          r.sub.6 = 63.100                                                                         d.sub.6 = 5.57                                                     r.sub.7 = -37.019                                                                        d.sub.7 = 1.28                                                                           n.sub.5 = 1.74400                                                                         ν.sub.5 = 44.73                          r.sub.8 = -240.280                                                                       d.sub.8 = D.sub.2                                                  r.sub.9 = 211.096                                                                        d.sub.9 = 7.05                                                                           n.sub.6 = 1.65844                                                                         ν.sub.6 = 50.86                          r.sub.10 = -29.039                                                                       d.sub.10 = 1.50                                                                          n.sub.7 = 1.78472                                                                         ν.sub.7 = 25.71                          r.sub.11 = -70.499                                                                       d.sub.11 = 0.10                                                    r.sub.12 = 35.714                                                                        d.sub.12 = 6.50                                                                          n.sub.8 = 1.51742                                                                         ν.sub.8 = 52.41                          r.sub.13 = -434.751                                                                      d.sub.13 = 1.20                                                    r.sub.14 = -164.868                                                                      d.sub.14 = 2.00                                                                          n.sub.9 = 1.80518                                                                         ν.sub.9 = 25.43                          r.sub.15 = 901.042                                                                       d.sub.15 = 30.44                                                   r.sub.16 = 80.736                                                                        d.sub.16 = 2.91                                                                          n.sub.10 = 1.74950                                                                        ν.sub.10 = 35.27                         r.sub.17 = -115.426                                                                      d.sub.17 = 7.40                                                    r.sub.18 = -30.425                                                                       d.sub.18 = 1.18                                                                          n.sub.11 = 1.74400                                                                        ν.sub.11 = 44.73                         r.sub.19 = -135.183                                                           ______________________________________                                        f             D.sub.1      D.sub.2                                            ______________________________________                                         72.45         1.501       25.912                                             118.14        14.969       12.445                                             193.00        26.416        0.998                                             f.sub.1 = 136.499,                                                                          f.sub.2 = -38.719                                               f.sub.T = 193.00,                                                                           f.sub.1 /f.sub.T = 0.71,                                                                   |f.sub.2 |/f.sub.T = 0.20        Δn.sub.d = 0.18144,                                                                   Δν.sub.d = 21.67                                       ______________________________________                                    

where, reference symbols r₁ through r₁₉ respectively represent radii ofcurvature of respective lens surfaces, reference symbols d₁ through d₁₈respectively represent thicknesses of respective lenses and airspacesbetween respective lenses, reference symbols n₁ through n₁₁ respectivelyrepresent refractive indices of respective lenses, reference symbols ν₁through ν₁₁ respectively represent Abbe's numbers of respective lenses,and reference symbol f represents the focal length of the lens system asa whole.